On the first run, that is quite normal. The citations are collected in the .aux file for BibTeX to work with, but BibTeX has not been called, yet.

erwann wrote:No file LaTeX.bbl.

You need to run BibTeX on your LaTeX[.aux] file.Afterwards, you need to run (pdf)LaTeX again twice to resolve the reference(s).If this reference is still undefined, have a look at the LaTeX.blg file (which is BibTeX's log file) and check for errors/warnings in there.

Interesting. Your BibTeX is from TL15, yet according to your previous log file, you're on TL18. Perhaps the TL15 version is found prior to its TL18 counterpart? Mayhap it doesn't look for the pathes set in TL18...

Anyway, you seem to have two TL installations on your Linux system, where the older TL15 was prepackaged for your Linux distribution.Unfortunately, your TL15's binaries are found first...What I find odd in this regard is: how did you manage to get the TL18's version of pdfLaTeX in the first place? You must've passed the path to it somehow, lest the TL15's version of should be taken instead (if your tex run on the console is any indication).You could pass the same path along for your bibtex call...Or, you could try to prepend the TL18's binary path (usually somewhere under /usr/local/texlive/2018/bin/<architecture>/).Or, you could try to remove bibtex & Co from /usr/bin.